gistfile1.m

@implementation NSString (JSRemoveIrrelevantTags)

- (NSString *)js_stringByRemovingIrrelevantTags
{
    NSMutableString *filteredString = [NSMutableString string];

    NSSet *filteredLinguisticTags = [NSSet setWithArray:@[NSLinguisticTagDeterminer, NSLinguisticTagPreposition]];

    [self enumerateLinguisticTagsInRange:NSMakeRange(0, self.length)
                                  scheme:NSLinguisticTagSchemeLexicalClass
                                 options:NSLinguisticTaggerJoinNames | NSLinguisticTaggerOmitOther | NSLinguisticTaggerOmitWhitespace
                             orthography:nil
                              usingBlock:^(NSString *tag, NSRange tokenRange, NSRange sentenceRange, BOOL *stop) {
                                  if (![filteredLinguisticTags containsObject:tag])
                                  {
                                      [filteredString appendFormat:@"%@ ", [self substringWithRange:tokenRange]];
                                  }
                              }];

    return filteredString;
}

@end

@implementation NSArray (JSNatualSort)

- (NSArray *)js_naturallySortedArray
{
    return [self sortedArrayUsingComparator:^NSComparisonResult(NSString *string1, NSString *string2) {
        return [[string1 js_stringByRemovingIrrelevantTags] caseInsensitiveCompare:[string2 js_stringByRemovingIrrelevantTags]];
    }];
}

@end